The invention relates to computer systems and more particularly to a process for achieving an automatic backup and restore of a pre-configuration of a computer system.
The restoration of a hard disk drive, or a partition of a hard disk drive, appears to be a generally complex and tricky procedure, which involves a great number of manual operations. When a hard disk drive suffers a breakdown and needs to be replaced, the user is compelled to enter into a laborious procedure for the purpose of re-establishing the configuration of his machine. He generally has to partition the new hard disk, to format the different partitions, to install the Operating System (OS) within the active partition, be it Windows (a trademark of Microsoft Corp.), Linux or OS/2 (a trademark of IBM Corp.) Once the Operating system has been installed, for instance Windows 98, the user may then take advantage of the internal backup/restore software facility which is incorporated in the OS for the purpose of restoring his data files. In the case of a Windows NT operating system, the user must then re-establish the Network Domain Controller (NDC) and re-trust the machine. When all the data files are restored, the will be completed by the restoring of the appropriate security settings (including the Access Control Lists which contain the list of users having permission to access the files) in the case of the UNIX, Windows NT, or OS/2 operating systems. It is clear that all those manual operations may be well beyond the normal possibilities of the ordinary user.
If the user has a stand-alone computer, he may take advantage of some type of hard disk image software which has revealed to be of much interest for taking and storing an image of a given partition. Such programs, marketed for instance by PowerQuest TM and NORTON TM under the commercial names of Drive image and Ghost, respectively, make a systematic copy of the contents of the clusters of a given partition. The copy of the partition and its restoration are substantially facilitated, since the user and, and the restoration of restore is thus facilitated and the user may get rid of all the manual steps which were mentioned above.
The image creation technique shows to be very useful for restoring an image of a given partition, but not without the cost of some disadvantages. A first drawback clearly results from the fact that, in that approach, a whole partition needs to be copied in one file, thus requiring a substantial storage media for each backup operation. No incremental backup is permitted and there is a need for a substantial amount of storage capacity, even between two successive backup procedures. Further, since the image taking procedure is handled under the DOS operating system, the computer is rendered no longer available for other tasks during a non negligible period. At last, the stand-alone backup procedure reveals to be not well adapted to a corporate environment involving a great number of different computers which are connected in a network. In that situation, the xe2x80x9cdisk imagexe2x80x9d approach would require as many image filesxe2x80x94each one of a considerable sizexe2x80x94as there are different machines comprised in the network. Generally speaking, in a corporate environment, an Information Technology (IT) manager provides the user support and, clearly, an set of individual backup images of all the machines is not feasible. The IT manager generally creates a so-called xe2x80x9cGoldxe2x80x9d or xe2x80x9cMasterxe2x80x9d image of a typical configuration which contains the Operation System with the appropriate drivers. The gold image can then be used for re-creating, when required, an image of the configuration in one machine, and the restoration of the configuration can then be completed with the reestablishment of the user""s files. In the case of Windows NT again, the machine needs still to be retrusted and the Security Identifier (SID) be redefined. Although the gold image shows to be very useful and substantially facilitates the work of the IT manager when the latter has to re-establish the configuration on an individual machine connected to a network, it appears that manual operations still need to be performed, or at least by a skilled user, for the sake of re-establishing the entire configuration of the machine. At least, the transfer of the image from the xe2x80x9cgoldxe2x80x9d or xe2x80x9cmasterxe2x80x9d disk for the purpose of re-establishing a remote access to a backup server implies a manual intervention of the IT manager and that, even when the crash does not result from any hardware breakdown, what is not so rare in the practice of the operating systems. Inevitably, the intervention of the IT manager substantially increases the costs of the computers maintenance.
Therefore there is still a need for a solution which permits to largely automate the backup and restore procedure so that it becomes directly applicable for a large number of operating systems, even when configured in a network or corporate environment, and that without requiring a skilled staff or an IT professional.
It is further desirable that the backup procedure can even take advantage of an Internet network so as to render the procedure fully transparent to the user who may continue to work with his machine. It is additionally expected that the backup procedure is not disturbed by the existence of the firewall arrangements which a company or a private organisation may arrange for securing its network.
It is an object of the present invention to provide an automated backup and restoration procedure which can be used by non experienced users, whatever complex is the environment in which the machine is being used.
It is another object of the present invention to provide an automatic backup/restore procedure which is well adapted to a wide range of different operating systems and which can be easily used through the Internet network or Intranet network, even when a firewall system is being arranged.
Basically, there is provided a backup procedure which performs a systematic analysis of the different elements of the configuration, for the purpose of transforming them into a corresponding set of backup objects. Backup objects include files, directories, volume names or labels, security attributes (Access Control Lists in Windows NT), as well as OS-specific markers which are dependent on a specific file, such as, for instance an entry in the FAT for MS-DOS. Each backup object is being systematically analysed and sent to a remote server with is identification, attributes, signature and content.
In one embodiment, the backup process takes advantage of the HyperText Transfer Protocol (HTTP) and each backup object is being encapsulated within a HTTP or HTTPS POST or PUT request which is transmitted to a remote server. This ensures the possibility to easily backup a system contained within an Intranet network, and that even if a firewall mechanism is being arranged within that Intranet. In particular, there is no need in modifying the actual settings of the firewall arrangement and the backup procedure is immediately applicable.
More precisely, the backup procedure involves the following steps:
getting from said server a remote data set of the objects, including the identifier, attributes and signatures, which are already stored within the data base 4;
computing a local data set of the objects which are representative of the user""s configuration;
transmitting to said server the objects identified in said local data set which are not identified within said remote data set, or which have not the same signature.
Since only the objects which are identified as being new or which have changed since the last backup procedure are being transmitted through the Internet network, the process presents the advantage of an incremental process, thereby minimising the amount of data which are being exchanged between two successive backup operations.
The backup procedure is associated with a process for automatically creating at least one CDROM medium complying with the EL TORITO format. For this purpose, a CDROM is created with a first bootable image disk which contains a set of system files drivers for allowing the control of different types of system files. In addition, the bootable partition comprises an executable file which servers as the shell after the drivers have been loaded, and which handles the process of the restoration procedure.
In one particular embodiment, additional CDROM are created for the purpose of storing large size partitions.
Once created upon request by the user, the bootable CDROM can be directly used for automatically re-establishing a given configuration. To achieve this the user has only to incorporate the CDROM within his drive and power-on the computer so that the latter starts on the CDROM. When the bootable CDROM is loaded by the users, an automatic reconfiguration process is automatically launched under the control of the above mentioned executable file, which execution involves the step of:
requesting a user id associated with a password;
computing a hash function with said user id and said password;
aborting said process if said computed hash function appears to be different to a value stored on the CDROM;
decrypting a table contained on said CDROM by means of said password, comprising the lists of backup objects, including the identifier, the attributes and the original names.
decrypting a data set of backup objects which are loaded and encrypted on said CDROM by means of said password;
extracting the identification of the operating system to reestablish, and correspondingly re-establishing settings dependent to the OS for ensuring a proper start of the OS at the next booting of the machine.
In one particular embodiment, the bootable image file of the EL TORITO CDROM contains the CDFS, as well as the HPFS, NTFS, FAT, FAT32 and i-NODE system files, or a subset of the latter. Therefore, there is provided a process for allowing a recovery of a wide set of operating systems, and a wide number of different user""s configuration. Therefore, the same bootable image file may be used for a wide range of different configurations and backups.
It therefore appears that the restoration of the configuration is immediate and does not need any preliminary restoration steps. In particular, there is no need to reestablish any remote access with a server prior to restoring the user""s configuration. With the restoration process of the invention, the restoration is immediate and directly re-establishes the user""s configuration.
Although the backup and restore process are adapted to a corporate environment, it can also be used in a stand-alone environment, and particularly in associated with a CDROM writing software. It can be used for automatically storing a local image of the backup objects corresponding to his configuration, for the purpose of producing, upon request, a bootable CDROM which may automatically re-establish the image when the user wishes so.
When the backup objects have been saved, the process controls the CDROM writer so that it arranges a bootable partition comprising at least a basic kernel operating system as well as a set of drivers allowing the access to CDFS, as well as NTFS, FAT, FAT32, HPFS or i-NODE file systems, or a subset of those. The bootable partition also comprises an executable recovery file which is automatically started after the files systems drivers are loaded. In addition to the bootable image disk, an ISO image comprises a first file having a hash function derived from the user and the password; a second file which has an encrypted table of the data set of the backup objects, including the identifier, the attributes and the original file names, then followed by an encrypted version of the different backup objects. After having checked the authenticity of the user, the process carried by the executable recovery file causes the decryption of the data set tables, and thus re-establishes the different backup objects with the corresponding attributes. The process is then finalised by the proper settings of OS specific settings for ensuring a proper start of the OS at the next booting of the computer.